Fluorescent lights of small compact construction have in recent years gained popularity because they can replace conventional incandescent light bulbs, but offer longer life and improved efficiency in regard to power consumption versus light output.
As often used, the compact fluorescent lights are provided with a plug-in base that mates with an adapter for receiving the light and having a threaded base that fits in the conventional incandescent lamp socket. The compact fluorescent light, in the following called "compact light", requires a so-called ballast which limits the amount of current drawn by the compact light. This ballast is conventionally mounted in the adapter so that it need not be replaced whenever the compact light is to be replaced. There are several types of compact lights and corresponding light fixtures. Some types fit directly into the fixture, with the ballast installed in the fixture. The invention is not directed to the particular type of compact light and the fixture adapted to the light, but to an arrangement for testing the compact light and fixture.
The arrangement of a compact light with its ballast, however, presents a problem to the user in that occasionally the ballast fails, either in the open mode or the shorted mode. When it begins to fail in the shorted mode, which is the most frequent failure mode, it also causes the destruction of the compact light since the current flow through the light in this situation rises to a high value that almost instantaneously burns out the compact light. When a service person subsequently replaces the burned-out compact light, not knowing that the ballast has failed in the shorted mode, the replacement compact light will soon or immediately be destroyed, as the current value rises.
On the other hand, if the ballast has failed in the open mode or power is missing, the service person will only note that the replacement compact light does not light up but will not know whether the compact light or the ballast are faulty, or power is missing.
It is accordingly the object of the present invention to provide a small, compact test device that can be inserted between the adapter and the compact light here used as a test light, and has two indicator lights and two push-button switches that quickly tells a service person whether a fault is in the ballast or in the compact light.